Energy management of household appliances

ABSTRACT

A microwave oven comprises a cooking cavity and a RF generation module configured to deliver microwave energy into the cooking cavity. A controller is operatively associated with the RF generation module. The controller receives and processes a signal indicative of current state of an associated energy supplying utility for determining whether to operate the microwave oven in one of a normal operating mode and an energy savings mode in response to the received signal. The controller is configured to at least temporarily block the signal when the RF generation module is activated if a frequency of the signal is at least partially degraded by a frequency of the RF generation module.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority from U.S. Provisional Patent Application Ser. No. 61/097,082 filed 15 Sep. 2008, now Ser. No. ______, filed 15 Sep. 2009 (Attorney Docket No. 231,308 (GECZ 2 00948)); which provisional patent application is expressly incorporated herein by reference, in its entirety. In addition, cross-reference is made to commonly owned, copending application Ser. No. ______, filed 15 Sep. 2009 (Attorney Docket No. 233326 (GECZ 00989)); Ser. No. ______, filed 15 Sep. 2009 (238022 (GECZ 2 00991)); Ser. No. ______, filed 15 Sep. 2009 (234622 (GECZ 2 00992)); Ser. No. ______, filed 15 Sep. 2009 (234930 (GECZ 2 00993)); Ser. No. ______, filed 15 Sep. 2009 (235012 (GECZ 2 00994)); Ser. No. ______, filed 15 Sep. 2009 (235215 (GECZ 2 00995)); Ser. No. ______, filed 15 Sep. 2009 (238022 (GECZ 2 00996)); Ser. No. ______, filed 15 Sep. 2009 (238404 (GECZ 2 00998)); Ser. No. ______, filed 15 Sep. 2009 (237845 (GECZ 2 00999)); Ser. No. ______, filed 15 Sep. 2009 (237898 (GECZ 2 01000)); and Ser. No. ______, filed 15 Sep. 2009 (237900 (GECZ 2 01001)).

BACKGROUND

This disclosure relates to energy management, and more particularly to energy management of household consumer appliances. The disclosure finds particular application to changing existing appliances via add-on features or modules, and incorporating new energy saving features and functions into new appliances.

Currently utilities charge a flat rate, but with increasing cost of fuel prices and high energy usage at certain parts of the day, utilities have to buy more energy to supply customers during peak demand. Consequently, utilities are charging higher rates during peak demand. If peak demand can be lowered, then a potential huge cost savings can be achieved and the peak load that the utility has to accommodate is lessened.

One proposed third party solution is to provide a system where a controller “switches” the actual energy supply to the appliance or control unit on and off. However, there is no active control beyond the mere on/off switching. It is believed that others in the industry cease some operations in a refrigerator during on-peak time.

For example, in a refrigerator most energy is consumed to keep average freezer compartment temperature at a constant level. Recommended temperature level is based on bacteria multiplication. Normally recommended freezer temperature for long (1-2 month) food storage is 0 degrees F. Research shows that bacteria rise is a linear function of the compartment temperature, i.e., the lower the temperature the lower the bacteria multiplication. Refrigerator designers now use this knowledge to prechill a freezer compartment (and in less degree a refrigerator compartment also) before defrost, thus keeping an average temperature during time interval that includes before, during, and after defrost at approximately the same level (for example, 0 degrees F.).

There are also currently different methods used to determine when variable electricity-pricing schemes go into effect. There are phone lines, schedules, and wireless signals sent by the electrical company. One difficulty is that no peak shaving method for an appliance such as a refrigerator will provide a maximal benefit. Further, different electrical companies use different methods of communicating periods of high electrical demand to their consumers. Other electrical companies simply have rate schedules for different times of day.

Electrical utilities moving to an Advanced Metering Infrastructure (AMI) system will need to communicate to appliances, HVAC, water heaters, etc. in a home or office building. All electrical utility companies (more than 3,000 in the US) will not be using the same communication method to signal in the AMI system. Similarly, known systems do not communicate directly with the appliance using a variety of communication methods and protocols, nor is a modular and standard method created for communication devices to interface and to communicate operational modes to the main controller of the appliance. Although conventional WiFi/ZigBee/PLC communication solutions are becoming commonplace, this disclosure introduces numerous additional lower cost, reliable solutions to trigger “load shedding” responses in appliances or other users of power. This system may also utilize the commonplace solutions as parts of the communication protocols.

BRIEF DESCRIPTION OF THE DISCLOSURE

According to one aspect, a microwave oven comprises a cooking cavity and a RF generation module configured to deliver microwave energy into the cooking cavity. A controller is operatively associated with the RF generation module. The controller receives and processes a signal indicative of current state of an associated energy supplying utility for determining whether to operate the microwave oven in one of a normal operating mode and an energy savings mode in response to the received signal. The controller is configured to at least temporarily block the signal when the RF generation module is activated if a frequency of the signal is at least partially degraded by a frequency of the RF generation module.

According to another aspect, microwave oven control method is provided. The microwave oven communicates with an associated energy supplying utility. A state for the associated utility is determined. The utility state is indicative of at least a peak demand period or an off-peak demand period. The microwave oven is operated in a normal mode during the off-peak demand period. The microwave oven is operated in an energy savings mode during the peak demand period. The communication with the associated utility is blocked during operating of the microwave oven to prevent unreliable communications during operation of the microwave oven.

According to yet another aspect, a microwave oven comprises a cooking cavity and a RF generation module configured to deliver microwave energy into the cooking cavity. A controller is operatively associated with the RF generation module. The controller is configured to receive and process an energy signal from an associated utility. The signal has a first state indicative of a utility peak demand period and a second state indicative of a utility off-peak demand period. The controller operates the microwave oven in one of an energy savings mode and a normal operating mode based on the received signal being in the first and second states respectively. The controller is configured to reduce power of the RF generation module in the energy savings mode.

According to still yet another aspect, an appliance comprises a power consuming feature/function and a controller operatively associated with the power consuming feature/function. The controller receives a signal indicative of current state of an associated energy supplying utility for determining whether to operate the appliance in one of a normal operating mode and an energy savings mode. The controller is configured to determine if the incoming energy signal has a frequency generally coincident with one of a fundamental frequency and a harmonic frequency of the activated power consuming feature/function. The controller is configured to at least temporarily block the receipt of the signal upon activation of the power consuming feature/function.

The present disclosure reduces power consumption during on-peak hours by reducing the energy demand on the power generation facility, and also enabling the user/consumer to pay less to operate the appliance on an annual basis.

This disclosure is a low-cost alternative to using expensive or complicated methods of determining when peak electrical rates apply. For example, when the refrigerator is in peak shaving mode (or it could be programmed to do this constantly), an ambient light sensor determines when it is morning, and then stays in energy-saving mode for a predetermined number of hours. Preferably, the system will need a counter to know that the room has been dark for a predetermined number of hours. When the lights come on for a certain length of time, then the system knows, for example, that it is morning.

This disclosure provides a peak-shaving appliance such as a refrigerator, including a method to determine when to go into peak-shaving mode without using additional components, or components that have another purpose, and provides a high percentage of the maximum benefit for negligible cost. The two components needed for this are an ambient light sensor and a timer. The kitchen will be dark for an extended period of time while everyone is sleeping. The light sensor and the timer will be used to determine that it is nighttime and morning can be determined by the light sensor. When the refrigerator determines it is morning, the timer will be used to initiate peak shaving mode after some delay time. For example, peak shaving mode could start three hours after it is determined morning starts. Similarly, the ambient light sensor can also be used for dimming the refrigerator lights. This disclosure advantageously uses ambient light to determine when to start peak shaving.

An appliance interface can be provided for all appliances leaving the module to communicate with the AMI system. The system provides for appliance sales with a Demand Side Management capable appliance. The Demand Side Management Module (DSMM) is provided to control the energy consumption and control functions of an appliance using a communication method (including but not limited to PLC, FM, AM SSB, WiFi, ZigBee, Radio Broadcast Data System, 802.11, 802.15.4, etc.). The modular approach will enable an appliance to match electrical utility communication requirements. Each electrical utility region may have different communication methods, protocol methods, etc. This modular approach allows an appliance to be adapted to a particular geographical area of a consumer or a particular electrical provider. The module can be added as a follow on feature and applied after the appliance is installed. Typical installations could include an integral mounted module (inside the appliance or unit) or an externally mounted module (at the wall electrical receptacle or anywhere outside the appliance or unit). The module in this disclosure provides for 2 way communications if needed, and will provide for several states of operation—for example, 1) normal operation, 2) operation in low energy mode (but not off), and 3) operation in lowest energy mode.

This module could be powered from the appliance or via a separate power supply, or with rechargeable batteries. The rechargeable batteries could be set to charge under off-peak conditions. With the module powered from the appliance, the appliance could turn it off until the appliance needed to make a decision about power usage, eliminating the standby power draw of the module. If powered separately, the appliance could go to a low energy state or completely off, while the module continued to monitor rates.

Use of RFID tags in one proposed system should offer significant savings since the RFID tags have become very low cost due to the proliferation of these devices in retail and will effectively allow the enabled appliance to effectively communicate with the utility meter (e.g., receive signals from the utility meter). This system makes it very easy for a customer to manage energy usage during peak demand periods and lowers the inconvenience level to the customer by not shutting off appliances in the home by the utility. When local storage and local generation are integrated into the system, then cost savings are seen by the customer. This system also solves the issue of rolling brownouts/blackouts caused by excessive power demand by lowering the overall demand. Also, the system allows the customer to pre-program choices into the system that will ultimately lower utility demand as well as save the customer money in the customer's utility billing. For instance, the customer may choose to disable the defrost cycle of a refrigerator during peak rate timeframes. This disclosure provides for the controller to “communicate” with the internal appliance control board and command the appliance to execute specific actions with no curtailment in the energy supply. This disclosure further provides a method of communicating data between a master device and one or more slave devices using RFID technology. This can be a number of states or signals, either using one or more passive RFID tags that resonate at different frequencies resonated by the master, or one or more active RFID tags that can store data that can be manipulated by the master device and read by the slave device(s). The states in either the passive or active RFID tags can then be read by the microcontroller on the slave device(s) and appropriate functions/actions can be taken based upon these signals.

Another exemplary embodiment uses continuous coded tones riding on carrier frequencies to transmit intelligence, for example, when one is merely passing rate information such as rate 1, 2, 3, or 4, using the tones to transmit the signals. One could further enhance the details of the messaging by assigning a binary number to a given tone, thus allowing one to “spell out” a message using binary coding with multiple tones. The appliance microcomputer would be programmed to respond to a given number that would arrive in binary format.

One advantage of this approach is that customers have complete control of their power. There have been proposals by utilities to shut off customers if they exceed demand limits or increase the number of rolling brownouts. This method also gives a customer finer granulity in their home in terms of control. A customer does not have to load shed a room just to manage a single device.

This disclosure also advantageously provides modes of load shedding in the appliance, lighting, or HVAC other than “on/off” to make the situation more acceptable from the perspective of the customer.

An advantage of the present disclosure is the ability to produce appliances with a common interface and let the module deal with the Demand Side Management.

Another advantage is the ability to control functions and features within the appliance and/or unit at various energy levels, i.e., as opposed to just an on/off function.

Another advantage is that the consumer can choose the module or choose not to have the module. If the module is chosen, it can be matched to the particular electrical utility service provider communication method of the consumer.

Another benefit is the increased flexibility with an associated electrical service provider, and the provision of several modes of operation (not simply an on/off mode). The module can be placed or positioned inside or outside the appliance and/or unit to provide demand side management.

Still other benefits relate to modularity, the ability to handle multiple communication methods and protocols without adversely impacting the cost of the appliance, opening up appliances to a variety of protocols, enabling demand side management or energy management, and/or providing for a standard interface to the appliance (for example, offering prechill and/or temperature set change during on-peak hours).

Low cost, reliable RF transmissions within the home, rather than using industrial solutions such as PLC or Zigbee solutions which are significantly more costly than the aforementioned system.

Still other features and benefits of the present disclosure will become apparent from reading and understanding the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-21 illustrate exemplary embodiments of an energy management system for household appliances.

FIG. 22 is a schematic illustration of an exemplary demand managed microwave oven.

FIG. 23 is an exemplary operational flow chart for the microwave oven of FIG. 22.

FIG. 24 is an exemplary control response for the microwave oven of FIG. 22.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In one embodiment, a more advanced system is provided to handle energy management between the utility and the homeowner's appliances. The system can include one or more of the following: a controller, utility meter, communication network, intelligent appliances, local storage, local generator and/or demand server. Less advanced systems may actually allow the appliance to “communicate directly with the utility meter or mesh network through the DSSM (Demand Side Management Module) (FIG. 1). The demand server is a computer system that notifies the controller when the utility is in peak demand and what is the utility's current demand limit. A utility meter can also provide the controller the occurrence of peak demand and demand limit. The demand limit can also be set by the home owner. Additionally, the homeowner can choose to force various modes in the appliance control based on the rate the utility is charging at different times of the day. The controller will look at the energy consumption currently used by the home via the utility meter and see if the home is exceeding the demand limit read from the server. If the demand limit is exceeded, the controller will notify the intelligent appliances, lighting and thermostat/HVAC (FIG. 2).

Each intelligent appliance has a communication interface that links itself to the controller (FIG. 3). This interface can be power-line carrier, wireless, and/or wired. The controller will interact with the appliance and lighting controls as well as thermostat (for HVAC) to execute the users preferences/settings.

Enabled appliances receive signals from the utility meter and help lower the peak load on the utility and lower the amount of energy that the consumer uses during high energy cost periods of the day. There are several ways to accomplish this, through wireless communication (ZigBee, WiFi, etc) or through PLC (power line carrier) communication. Alternatively, using passive RFID tags that resonate at different frequencies resonated by the master, or one or more active RFID tags that can store data that can be manipulated by the master device and read by the slave devices(s) is an effective and potentially lower cost communication solution since there is no protocol. Rather, a pulse of energy at a particular frequency will allow a low cost method with an open protocol for transmitting/communicating between a master device and one or more slave devices, and appropriate functions/actions can be taken based upon these signals.

The interaction between controller and appliances can occur in two ways. For example, in one scenario during a peak demand period, the controller will receive a demand limit from the utility, demand server or user. The controller will then allocate the home's demand based on two factors: priority of the appliance and energy need level (FIG. 4). The priority dictates which appliances have higher priority to be in full or partial energy mode than other appliances. Energy need dictates how much energy is required for a certain time period in order for that appliance to function properly. If the appliance's energy need is too low to function properly, the appliance moves to a normal mode or a higher energy need level. The energy saving mode is typically a lower energy usage mode for the appliance such as shutdowns of compressors and motors, delayed cycles, higher operating temperatures in summer or lower operating temperatures in winter until the peak demand period is over. Once the demand limit is reached, the appliances will stay in their energy mode until peak demand is over, or a user overrides, or appliance finishes need cycle or priority changes. The controller constantly receives status updates from the appliances in order to determine which state they are in and in order to determine if priorities need to change to accomplish the system goals.

In a second scenario, for example, a set point is provided. During a peak demand period, the controller will tell each appliance to go into peak demand mode (FIG. 5). The appliance will then go into a lower energy mode. The customer can deactivate the energy savings mode by selecting a feature on the appliance front end controls (i.e. user interface board) before or during the appliance use or at the controller. The controller can also communicate to a local storage or power generation unit. This local unit is connected to the incoming power supply from the utility. The controller notifies the storage unit to charge when it is not in peak demand, if a storage unit is included and available. If the storage unit has enough energy to supply the appliances during peak demand, then the controller will switch the home's energy consumption from the utility to the storage unit. The unit can also be local generator/storage such as solar, hydrogen fuel cell, etc.

The central controller handles energy management between the utility and home appliances, lighting, thermostat/HVAC, etc. with customer choices incorporated in the decision making process. The controller may include notification of an energy saving mode based on demand limit read from one or more of a utility meter, utility, demand server or user. An energy savings mode of an appliance can thereby be controlled or regulated based on priority and energy need level sent from the controller and/or the customer (FIG. 6). Likewise, consideration to use of local energy storage and use of a local generator to offset peak demand limit can be incorporated into the energy management considerations, or provide the ability to override mode of energy savings through the controller or at the appliance, lighting, or thermostat/HVAC (FIGS. 7 and 8).

The present disclosure has the ability for the home to shed loads in pending brown-out or black-out situations, yet have intelligence to prevent an improper action such as shutting down the refrigerator for extended timeframes that might compromise food storage safety.

How much energy the appliance consumes in peak demand is based on priority of the device and the energy need level. If the appliance's priority is high, then the appliance will most likely not go into a saving mode. The energy need level is based on how little energy the appliance can consume during peak demand and still provide the function setting it is in (i.e. in a refrigerator, ensuring that the temperature is cool enough to prevent spoiling). It will also be appreciated that an appliance may have multiple energy need levels.

The controller will be the main product with the communication and settings control incorporated within future appliances. Specific meters will be selected so that the controller can read the demand usage. It is intended that the demand server will possibly be purchased or leased to the utility.

A method is provided for constructing an appliance designed to perform any key function, the appliance comprises of several mechanical and electrical elements controlled by a main controller. This main controller has a port for receiving information regarding the operational state of the appliance. The port also has a user interface or switch which could be used to override the information received by the controller through the port. Two-way or one-way communication devices may be connected to the port. These communication devices will receive signals from a remote controller, process those signals and as a result communicate an operational state to the main controller of the appliance. This operational state is communicated to the main controller by one or more remote controllers in a specific format determined by the appliance. These signals from the remote controller(s) could be based on a variety of communication methods and associated protocols. On receiving the operational state signal, the appliance main controller causes the appliance to run a predetermined operational mode. These operational modes are designed into the appliance(s) and result in different resource consumption levels or patterns, even delaying use. Resources could include energy, water, air, heat, sunlight, time, etc. In future appliance models, the consumer might be given the authority to modify the appliance responses to a given rate signal. The consumer would be presented a “check box” of potential response modes and allowed to choose within set parameters. For instance, the consumer might be allowed to choose the amount of temperature adjustment a refrigerator will make in response to a high utility rate.

A method of communicating data between a master device and one or more slave devices may advantageously use continuous tone-coded transmission system. This can be a number of states or signals, either using one or more continuous tones that signify different rate states coming from the home area network (from meter) or the utility. Additionally, one could send a combination of tones to transmit binary messages using a few tones. The slave devices will incorporate a receiver that receives the carrier frequency and then decodes the continuous tone which corresponds to the particular state of the utility rate. Once the “receiver board” detects the tone, then the downstream circuitry will trigger the appropriate response in the appliance. The carrier frequency in this scheme can be numerous spectrums, one being the FM broadcast band or a specific FM band allocated by the FCC for low level power output. The advantage of broadcast band FM is the low cost of such devices and the potential to penetrate walls, etc. within a home with very low levels of power due to the long wavelength of the 89-106 Mhz carrier. This process is used today in 2-way radio communications to reduce the annoyance of listening to multiple users on shared 2-way radio frequencies. The process in these radios is referred to as CTCSS (continuous tone-coded squelch system) and would find application in this end use.

Generally, it is not known to have modular interfaces that can receive signals from a control source. Also, no prior arrangements have functioned by addressing the control board of the appliance with a signal that directs the appliance to respond.

Thus, by way of example only, the structure and/or operation of a refrigerator (FIG. 9, although other appliances are also represented) may be modified or altered by reducing the temperature, especially in the freezer compartment pre on-peak time and further temporarily provide a compartment temperature increase to shave on-peak load. Specifically, defrost operation could be delayed until off-peak time. Alternatively or conjunctively, the freezer and refrigerator temperature setpoints may be set to maintain less compressor on time during on-peak demand times. Similarly, the refrigerator/freezer could be programmed so that lights will not be permitted to come on or the lights must be dimmed lights during on-peak demand times. During on-peak demand times, the fan operating speeds can be reduced, and/or compressor operating speed reduced in order to reduce energy consumption. Still another option is to reduce the delay time for the door alarm to sound during on-peak time. Other power load reducing measures in a refrigerator may include (reducing before on-peak hours) the temperature of the freezer and refrigerator compartments in a refrigerator (prechill) and slightly increase temperature setting during on-peak rates. For example, just before peak rate time, the temperature setting could be decreased by 1-2 degrees (during off-peak rates). Some communication line with the electrical company could be established. Thus, the electrical company may be able to send a signal in advance to prechill the refrigerator (or in the case of an air conditioner, decrease the room temperature during off-peak rates as a pre-chill maneuver) and, in turn, increase the temperature setting during on-peak rates.

Still other energy consuming practices of the exemplary refrigerator that may be altered include turning the ice-maker off during on-peak demand times, or disabling the crushed ice mode during on-peak demand times. Alternatively, the consumer may be given the ability to select via a user interface which items are incorporated into the on-peak demand via an enable/disable menu, or to provide input selection such as entry of a zip code (FIG. 10) in order to select the utility company and time of use schedule (FIG. 11), or using a time versus day of the week schedule input method (FIGS. 12-13).

The user interface may also incorporate suggested energy saving tips or show energy usage, or provide an indicator during on-peak mode, or provide a counter to illustrate the energy impact of door opening, or showing an energy calculator to the consumer to serve as a reminder of the impact of certain selections/actions on energy use or energy conservation (FIGS. 14-19).

One path that is being pursued from the appliance perspective is to allow the onboard CPU (microprocessor) of the appliance to determine how to respond to an incoming signal asking for a load shedding response. For example, the CPU will turn on, turn off, throttle, delay, adjust, or modify specific functions and features in the appliance to provide a turndown in power consumption (FIG. 20). FIG. 21 defines specifically exemplary modes of what are possible. The main feature here is the enabling of the main board microprocessor or CPU to execute actions in the appliance to deliver load shedding (lowering power consumption at that instant). The actions available in each appliance are only limited to the devices that the CPU has control over, which are nearly all of the electrical consuming devices in an appliance. This may work better where the appliance has an electronic control versus an electromechanical control.

Of course, the above description focuses on the refrigerator but these concepts are equally applicable to other home appliances such as dishwashers, water heaters, washing machines, clothes dryers, televisions (activate a recording feature rather than turning on the television), etc., and the list is simply representative and not intended to be all encompassing.

Likewise, although these concepts have been described with respect to appliances, they may find application in areas other than appliances and other than electricity usage. For example, a controller that acts as an intermediary between the utilities meter and the appliance interprets the utility signal, processes it and then submits this signal to the appliance for the prescribed reaction. In a similar fashion, the controller may find application to other household utilities, for example, natural gas and water within the home. One can equip the water and gas meters to measure flow rates and then drive responses to a gas water heater or gas furnace precisely like the electrical case. This would assume that one might experience variable gas and water rates in the future. Secondly, the flow meters being connected to the controller could provide a consumer with a warning as to broken or leaking water lines by comparing the flow rate when a given appliance or appliances are on to the normal consumption. In cases where safety is a concern, the system could stop the flow of gas or water based on the data analysis.

Another feature might be the incorporation of “remote subscription” for the utility benefit. In some cases, the utility will be providing customers discounts/rebates for subscribing to DSM in their appliances, hot water heaters, etc. The “remote subscription” feature would allow the utility to send a signal that would “lockout” the consumer from disabling the feature since they were on the “rebate” program.

Another feature that the controller lends itself to is the inclusion of “Remote diagnostics”. This feature would allow the appliance to send a signal or message to the controller indicating that something in the appliance was not up to specifications. The controller could then relay this signal to the utility or to the appliance manufacturer via the various communication avenues included into the controller (i.e., WIFI, WIMAX, Broadband, cell phone, or any other formats that the controller could “speak”).

In the case of a remote subscription, the utilities today rely on the honesty of their subscribers to leave the DSM system functional. Some people may receive the discounts/rebate and then disable the feature that drives the load shedding. With this system, the utility can ensure that the feature will be enabled and provide the proper load shedding.

An exemplary embodiment of a demand managed appliance 100 is schematically illustrated in FIG. 22. The appliance 100 comprises at least one power consuming feature/function 102 and a controller 104 operatively associated with the power consuming feature/function. The controller 104 can include a micro computer on a printed circuit board which is programmed to selectively control the energization of the power consuming feature/function. The controller 104 is configured to receive and process a signal 106 indicative of indicative of a utility state, for example, availability and/or current cost of supplied energy. The energy signal may be generated by a utility provider, such as a power company, and can be transmitted via a power line, as a radio frequency signal, or by any other means for transmitting a signal when the utility provider desires to reduce demand for its resources. The cost can be indicative of the state of the demand for the utility's energy, for example a relatively high price or cost of supplied energy is typically associated with a peak demand state or period and a relative low price or cost is typically associated with an off-peak demand state or period.

The controller 104 can operate the appliance 100 in one of a plurality of operating modes, including a normal operating mode and an energy savings mode, in response to the received signal. Specifically, the appliance 100 can be operated in the normal mode in response to a signal indicating an off-peak demand state or period and can be operated in an energy savings mode in response to a signal indicating a peak demand state or period. As will be discussed in greater detail below, the controller 104 is configured to at least one of selectively delay, adjust and disable at least one of the one or more power consuming features/functions to reduce power consumption of the appliance 100 in the energy savings mode.

Activation of the power consuming feature/function can generate a first frequency. The controller 104 receives the signal 106 indicative of cost of supplied energy for determining whether to operate the appliance 100 in one of the normal operating mode and the energy savings mode. In some instances, the signal 106 has a frequency generally coincident or harmonic with the fundamental frequency of the power consuming feature/function or any harmonics thereof. Thus, the incoming energy signal 106 can be impacted or degraded by the first frequency. The controller 104 is configured to at least partially or temporarily block the receipt of the signal upon activation of the power consuming feature/function to prevent unreliable communications during activation of the power consuming feature/function.

As shown in FIG. 22, the appliance 100 is a microwave oven 110. The microwave oven 110 generally includes an outer case 112 and a control panel or user interface 116. The microwave oven further includes a door (not shown) mounted within a door frame 104, a grille (not shown) and a window (not shown) located in the door for viewing food in an oven cooking cavity 120. The control panel 116 can include a display and control buttons for making various operational selections. Cooking algorithms can be preprogrammed in the oven memory for many different types of foods. When a user is cooking a particular food item for which there is a preprogrammed cooking algorithm, the preprogrammed cooking algorithm is selected by pressing one of the control buttons. Instructions and selections are displayed on the display. A light source 124 is provided for illuminating the user interface 116.

To heat the food placed within the cooking cavity 120, the microwave oven includes an RF generation module or magnetron 130 which is typically located on a side or top of the cooking cavity 120. The magnetron can be mounted to a magnetron mount on a surface of the cooking cavity. The RF generation module 130 is configured to deliver microwave energy into the cooking cavity 120. The microwave oven further includes a fan 140 for cooling the magnetron and a light source 144 for illuminating the cooking cavity 120. For an over the range type microwave oven, a separate light source 146 can be provided for illuminating a top cooking surface of a range. The microwave oven 110 is provided by way of illustration rather than limitation, and accordingly there is no intention to limit application of the present disclosure to any particular microwave oven.

In the normal operating mode, a user places food on a turntable located in the cooking cavity 120. The user then selects a preprogrammed cooking algorithm, a cooking time and/or a power level and then selects “Start” from the control panel 116. The magnetron 130 is then energized in accordance with the user selections. The fan 140 is provided to cool the magnetron. The controller 104 is configured to cyclically energize and de-energize the magnetron 130 during the selected cooking cycle. The duty cycle for the magnetron 130, that is, the percent on time for the magnetron to a control time period, can depend on at least one of a pre-programmed cooking algorithm and a user selected operation mode. More specifically, in an exemplary embodiment, the controller 104 can operate the magnetron on a 32 second control period. The length of time the magnetron 130 is on during a particular control period varies depending on the power level selected. The duty cycle, or ratio of the on time, can be precisely controlled and is pre-determined by the operating parameters selected by the user. Different foods will cook best with different ratios. The microwave oven 110 allows control of these power levels through both pre-programmed cooking algorithms and through user-customizable manual cooking. Microwave energy from the magnetron 130 heats the food. The magnetron can be energized for 100% of the duty cycle, or can cycle on and off for an amount of time based on the selected power level during each duty cycle.

In order to prevent overheating of the microwave oven 110, the controller 104 can override the user selected power levels in a customized cooking algorithm if operation at certain power levels exceeds a predetermined time period. The controller adjusts the power level of the magnetron to a first power level after a first period of time, and if the first power level is above the threshold power level for the magnetron 130, the controller adjusts the first power level of the module to a second lower power level after a second period of time. By way of example, the magnetron 130 can be set to any combination of power levels (e.g., from 0 (not energized) to 10 (energized at 100%)). If the user sets each at power level ten (10), after a first period of time, for example 10 minutes, the magnetron 130 is reduced to 70% of the set power level. If the reduced power level is still higher than the threshold power level, after a second period of time, for example 20 minutes, the magnetron 130 is reduced to 50% of the set power level.

In order to reduce the peak energy consumed by the microwave oven 110, the controller 104 is configured to selectively adjust and/or disable at least one of the one or more above described power consuming features/functions to reduce power consumption of the microwave oven 110 in the energy savings mode. Reducing total energy consumed also encompasses reducing the energy consumed at peak times and/or reducing the overall electricity demands. To this extent, the controller 104 is configured to reduce a power level of the magnetron 130 in the energy savings mode. For example, in response to a load shedding signal, the controller 104 can switch from a high voltage tap point on the transformer to a low voltage tap point (i.e., a voltage change to the magnetron 130). The controller 104 is also configured to reduce speed of the fan 140 and reduce the intensity of at least one of the light sources 124, 144, 146 in the energy savings mode.

In some instances, the quality of the incoming energy signal 106 can be impacted or degraded by the fundamental frequency of the magnetron 130. A typical microwave oven uses between 500 and 1000 W of microwave energy at 2.45 GHz to heat the food. There may be a high likelihood that the frequency bands of microwave signals generated by the magnetron create interference with frequency bands used for Wibro communication, HSDPA (High Speed Downlink Packet Access), wireless LAN (Local Area Network. IEEE 802.22 standards), Zigbee (IEEE802.15 standards), Bluetooth (IEEE802.15 standards) and RFID (Radio Frequency Identification). If the controller 104 determines that the frequency of the energy signal 106 can be generally harmonic with and/or at least partially degraded by the frequency of the activated magnetron 130, the controller 104 can at least partially block the energy signal. Alternatively, the controller 104 can temporarily block communication during activation of the magnetron 130 regardless of the frequency if the energy signal 106. The energy signal can be queued in a memory 150. After deactivation of the magnetron 130, the controller 104 can review and process the queued energy signal stored in the memory 150 to at least partially determine the operating mode for the microwave oven 110. If the microwave oven 110 is to operate in the energy savings mode, the power lever of the magnetron 130 can be selectively adjusted to reduce the power consumed by the magnetron during subsequent operation.

The magnetron 130 generates high power electromagnetic waves whenever its input voltage is above some threshold. AC mains normally drive the magnetron. The AC mains can also be rectified before being supplied to the magnetron. In either case, when the input voltage is less than the threshold, no magnetic waves are generated. So whenever the microwave oven 110 is being used, the magnetron 130 does not generate waves throughout the time it is switched on. As the AC mains are periodic with a frequency of about 60 Hz, the time intervals when no waves are generated by magnetron 130 are also periodic with the same frequency. The value of threshold and the use of a rectifier is generally manufacture dependent and hence varies from microwave oven to microwave oven.

Whenever the microwave oven 110 is generating interference via the activated magnetron 130, the controller may have problems receiving and processing the energy signal 106. Generally, the only time the controller 104 can receive and process the energy signal 106 is when there is no interference. For example, if the microwave oven interference is present for 60% of the time the magnetron 130 is activated, the controller 104 can receive and process the energy signal 106 only 40% of time. Due to the periodic nature of microwave oven interference, the controller 104 can be configured to predict the windows in time for which the interference will and will not be present while the magnetron 130 is active.

For example, according to one exemplary embodiment, the magnetron 130 of the RF generation module 130 operates on a duty cycle throughout a selected cooking cycle. The magnetron cycles on and off during the duty cycle. The controller 104 is configured to block signal communication when the RF generation module 130 is on. Alternatively, the controller 104 is configured to block the signal communication during the entire duty cycle of the RF generation module. The microwave oven 110 continues operation in one of the normal operating mode and the energy savings mode during a time period that the signal is blocked. Particularly, the microwave oven temporarily stops communication with the energy signal and continues to operate in its current operating mode during the time period that the signal is blocked. As set forth above, the controller 104 is configured to queue the blocked signal during operation of the magnetron 130. The queue is processed after operation of the microwave oven 110 for at least partially determining current operating mode for the microwave oven.

With reference to FIG. 23, a control method in accordance with the present disclosure comprises communicating with an associated utility and receiving and processing the signal indicative of cost of supplied energy (S200), determining a state for an associated energy supplying utility, such as a cost of supplying energy from the associated utility (S202), the utility state being indicative of at least a peak demand period or an off-peak demand period, operating the microwave oven 110 in a normal mode during the off-peak demand period (S204), operating the microwave oven 110 in an energy savings during the peak demand period (S206), selectively adjusting any number of one or more power consuming features/functions of the microwave oven to reduce power consumption of the appliance in the energy savings mode (S208), and returning to the normal mode after the peak demand period is over (S210). The selective adjustment can include reducing power to the magnetron 130 in the energy savings mode, reducing speed of the fan 140 in the energy savings mode, and reducing an intensity of at least one of the light sources 124, 144, 146 in the energy savings mode.

The control method further includes temporarily blocking the communication with the associated utility during operating of the microwave oven to prevent unreliable communications during operation of the microwave oven (S212), queuing the communication with the associated utility during operating of the microwave oven (S214), and processing the queue after operation of the microwave oven for at least partially determining current operating mode for the microwave oven (S216).

It is to be appreciated that a selectable override option can be provided on the user interface 116 providing a user the ability to select which of the one or more power consuming features/functions are adjusted by the controller in the energy savings mode. The user can override any adjustments, whether time related or function related, to any of the power consuming functions The operational adjustments, particularly an energy savings operation can be accompanied by a display on the panel which communicates activation of the energy savings mode. The energy savings mode display can include a display of “ECO”, “Eco”, “EP”, “ER”, “CP”, “CPP”, “DR”, or “PP” on the appliance display panel in cases where the display is limited to three characters. In cases with displays having additional characters available, messaging can be enhanced accordingly. Additionally, an audible signal can be provided to alert the user of the appliance operating in the energy savings mode.

The duration of time that the appliance 100 operates in the energy savings mode may be determined by information in the energy signal. For example, the energy signal may inform the appliance 100 to operate in the energy savings mode for a few minutes or for one hour, at which time the appliance returns to normal operation. Alternatively, the energy signal may be continuously transmitted by the utility provider, or other signal generating system, as long as it is determined that instantaneous load reduction is necessary. Once transmission of the signal has ceased, the appliance 100 returns to normal operating mode. In yet another embodiment, an energy signal may be transmitted to the appliance to signal the appliance to operate in the energy savings mode. A normal operation signal may then be later transmitted to the appliance to signal the appliance to return to the normal operating mode.

The operation of the appliance 100 may vary as a function of a characteristic of the supplied energy, e.g., availability and/or price. Because some energy suppliers offer what is known as time-of-day pricing in their tariffs, price points could be tied directly to the tariff structure for the energy supplier. If real time pricing is offered by the energy supplier serving the site, this variance could be utilized to generate savings and reduce chain demand. Another load management program offered by energy supplier utilizes price tiers which the utility manages dynamically to reflect the total cost of energy delivery to its customers. These tiers provide the customer a relative indicator of the price of energy and are usually defined as being LOW, MEDIUM, HIGH and CRITICAL. These tiers are shown in the chart of FIG. 24 to partially illustrate operation of the microwave oven 110 in each pricing tier. For example, with such a tiered system from the energy supplier, when a user activates any feature on the appliance 100, the controller 104 polls the ports for the incoming energy signal 106. Based on the energy signal, the appliance will perform in one of the four pricing tiers. In the event the user has selected a feature that requires the magnetron 130 during any tier other than LOW, the controller 104 can change the level of voltage applied to the magnetron via a transformer tap. The duty cycling associated with the feature selected can remain the same and the power of the magnetron 130 is adjusted. However, it will be appreciated that the controller could be configured to implement a unique operating mode for each tier which provides a desired balance between compromised performance and cost savings/energy savings. If the utility offers more than two rate/cost conditions, different combinations of energy saving control steps may be programmed to provide satisfactory cost savings/performance tradeoff.

It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. 

1. A microwave oven comprising: a cooking cavity; a RF generation module configured to deliver microwave energy into the cooking cavity; and a controller operatively associated with the RF generation module, the controller receiving and processing a signal indicative of current state of an associated energy supplying utility for determining whether to operate the microwave oven in one of a normal operating mode and an energy savings mode, wherein the controller is configured to at least temporarily block the signal when the RF generation module is activated if a frequency of the signal can be at least partially degraded by a frequency of the RF generation module.
 2. The microwave oven of claim 1, wherein the RF generation module operates on a duty cycle throughout a selected cooking cycle, the RF generation module cycling on and off during the duty cycle, the controller being configured to block signal communication when the RF generation module is on.
 3. The microwave oven of claim 2, wherein controller is configured to block the signal communication during the entire duty cycle of the RF generation module.
 4. The microwave oven of claim 1, wherein the controller is configured to continue operation of the microwave oven in one of the normal operating mode and the energy savings mode during a time period that the signal is blocked.
 5. The microwave oven of claim 4, wherein the controller is configured to queue the blocked signal during operation of the RF generation module.
 6. The microwave oven of claim 1, wherein the controller is configured to selectively adjust and/or deactivate one or more power consuming features/functions of the microwave oven to reduce power consumption in the energy savings mode.
 7. The microwave oven of claim 6, wherein the microwave oven further includes a fan, the controller being configured to reduce speed of the fan in the energy savings mode.
 8. The microwave oven of claim 6, wherein the microwave oven further includes a light source, the controller being configured to reduce the intensity of the light source in the energy savings mode.
 9. The microwave oven of claim 6, wherein the controller is configured to reduce a power level of the RF generation module in the energy savings mode.
 10. The microwave oven of claim 6, further comprising a user interface operatively connected to the controller, the user interface including a selectable override option to enable a user to prevent the controller from selectively adjusting and/or deactivating the one or more power consuming features/functions in the energy savings mode.
 11. The microwave oven of claim 6, wherein the user interface further includes a display communicating activation of the energy savings mode.
 12. The microwave oven of claim 11, wherein the energy savings mode display includes a display selected from the group consisting of ‘“ECO”, “Eco”, “EP”, “ER”, “CP”, “CPP”, “DR”, and “PP”.
 13. A microwave oven control method, comprising: communicating with an associated utility; determining a state for an associated energy supplying utility, the utility state being indicative of at least a peak demand period or an off-peak demand period; operating the microwave oven in a normal mode during the off-peak demand period; operating the microwave oven in an energy savings mode during the peak demand period; and blocking the communication with the associated utility during operating of the microwave oven to prevent unreliable communications during operation of the microwave oven.
 14. The method of claim 13, further comprising selectively adjusting any number of one or more power consuming functions of the microwave oven to reduce power consumption of the microwave oven in the energy savings mode.
 15. The method of claim 14, further comprising reducing power to a RF generation module of the microwave oven in the energy savings mode.
 16. The method of claim 14, further comprising: reducing speed of a fan of the microwave oven in the energy savings mode, and reducing an intensity of a light source of the microwave oven in the energy savings mode.
 17. The method of claim 13, further comprising: queuing the communication with the associated utility during operating of the microwave oven, and processing the queue after operation of the microwave oven for at least partially determining current operating mode for the microwave oven.
 18. A microwave oven comprising: a cooking cavity; a RF generation module configured to deliver microwave energy into the cooking cavity; and a controller operatively associated with the RF generation module, the controller configured to receive and process an energy signal from an associated utility, the signal having a first state indicative of a utility peak demand period and a second state indicative of a utility off-peak demand period, the controller operating the microwave oven in one of an energy savings mode and a normal operating mode based on the received signal being in the first and second states respectively, wherein the controller is configured to reduce power of the RF generation module in the energy savings mode.
 19. The microwave of claim 18, wherein the microwave oven further includes a fan and a light source, the controller being configured to reduce at least one of the speed of the fan and the intensity of the light source in the energy savings mode.
 20. The microwave of claim 18, wherein the controller is configured to determine a frequency of the incoming energy signal, the controller temporarily blocking receipt of the energy signal when the RF generation module is activated if the determined frequency of the energy signal is impacted by a frequency of the RF generation module.
 21. The microwave oven of claim 20, wherein the controller is configured to queue the energy signal during activation of the RF generation module and process the queue after deactivation of the RF generation module for at least partially determining current operating mode for the microwave oven.
 22. An appliance comprising: a power consuming feature/function; and a controller operatively associated with the power consuming feature/function, the controller receiving a signal indicative of current state of an associated energy supplying utility for determining whether to operate the appliance in one of a normal operating mode and an energy savings mode, wherein the controller is configured to determine if the incoming energy signal has a frequency generally coincident with one of a fundamental frequency and a harmonic frequency of the activated power consuming feature/function, wherein the controller is configured to at least temporarily block the receipt of the signal upon activation of the power consuming feature/function. 